This invention relates to a ventilation appliance for rooms with a radial fan arranged in a box-shaped housing and an enveloping spiral column encircling the blower wheel inside the housing, formed as an insert body.
In ventilation appliances for rooms it is already known, for example as disclosed in DE-OS 30 17 431, to arrange a radial fan in a box-like housing the radial fan consisting of the blower wheel itself and encircled by an enveloping spiral. The radial fan is detachably arranged in the box-like housing.
A deficiency in known ventilation appliances lies in the fact that both the blower wheel and the encircling, enveloping spiral are constructed entirely of rigid (reverberative) material, such as sheet metal.
Significant sound-deadening effect can therefore only be obtained in known ventilation appliances when special linings, formed out of sound deadening material, are applied to the air conducting conduits at the back of the radial fan itself in the box-like housing.
For functional reasons it is not always possible to provide sound deadening linings in the flow ducts at the back of the radial fan. Moreover, there is frequently not enough space beyond the radial fan inside the box-like housing to arrange sound deadening, lined, flow ducts of sufficient lengths to acheive significant sound deadening effect.
The instant invention has, as a primary objective, to provide a room ventilating appliance of the above described type that acheives a good sound deadening effect even when no long flow paths are available within the box-like housing, or when, for functional reasons, the paths cannot be provided with sound deadening linings.